ASTR 1020 Lecture Notes - Lecture 15: White Dwarf, Red Giant, Star System
Document Summary
Form from clouds of interstellar gas (like other stars), but do not reach a sufficient mass, density, and internal heat to initiate nuclear fusion. Tend to be more white than yellow. Aka g v stars (for their spectral type g and luminosity class v). When a main-sequence star burns out all its hydrogen by combining hydrogen to form helium, the star then begins to burn its helium into carbon and oxygen, causing the star to expand in size becoming a red giant. Within two hundred million years (relatively short time in space) the red giant puffs out its outer layers in a gas cloud (nebula) before collapsing in on itself to form a white dwarf. The largest red giants are known as red supergiants. These stars are the largest in the universe in volume. Represents the final evolutionary state of low and intermediate mass stars. Surface temperatures between 7,600 and 10,000 degrees celsius.
